1. Field of the Invention
The present invention relates to a film pressing device for pressing add positioning a photosensitive film which is adapted for use in an apparatus in which an exposure for forming an image on the photosensitive film and a projection of the image formed are effected at an identical position.
2. Description of the Related Art
One type of photographic apparatus has heretofore been known which is capable of recording an image on a predetermined frame of a photographic film and of projecting or copying the recorded image. This type of apparatus is disclosed in, for example, U.S. Pat. Nos. 3,528,355, 3,697,176, 3,964,828, 3,972,610 and 4,461,561.
Also, regarding the photographic film, there are various known photosensitive films such as a silver halide film, an electrophotographic film, an electrophotographic migration imaging film (cf. Journal of Applied Photographic Engineering, Vol. 9, No. 1, 1983), and the like. Hereinafter, an apparatus to which the electrophotographic film is applied as the photosensitive film is described.
A processing head is disposed in such photographic apparatus to subject an electrophotographic film to various kinds of processing such as charging/exposure and development and such processing head is known from the specifications of U.S. Pat. No. 4,600,291.
The processing head disclosed in the above-mentioned publications has a charging/exposure section, a developing section, a drying section and a fixing section which are arranged in series in the mentioned order along the path of feed of the electrophotographic film, at a pitch or interval which corresponds to the pitch of frames on the electrophotographic film.
In the charging/exposure section, the portion of the electrophotgraphic film located in this section, constituting one frame, is charged and then exposed to an image light from an original, so that an electrostatic latent image corresponding to the pattern of an image carried by the original is formed in this portion of the film. The film is then fed so as to bring the exposed frame to the developing section where a liquid developing agent is applied to the electrophotographic film so as to develop the latent image thereby making it visible. Subsequently, the frame is brought to the drying section where drying air is blown to the electrophotographic film wetted by the liquid developing agent so as to remove moisture component from the film. Finally, the frame is brought to the fixing section where the developed image is fixed to the electrophotographic film by means of, for example, a fixing lamp.
The processing head also is capable of applying a projecting light to the developed image, thereby enabling the developed image to be projected onto a screen. More specifically, the projecting light is applied to the image on the portion of the electrophotogaphic film which is in the charging/exposure section of the processing head, through an aperture formed in a pressing means for pressing the electrophotographic film onto the processing head. The pressing means is disposed at a position which is spaced from the processing head by a large distance so as to prevent the electrophotographic film from becoming damaged due to contact with the processing head or with the pressing means during running of the electrophotographic film or during the loading of the electrophotographic film.
The projection of the developed image also requires an optical system for applying the projecting light onto the film, and a light shielding member for shielding from the projecting light the portions of the electrophotographic film other than the image to be projected. Such optical system and light shielding member have to be installed away from the path of the film so that they may not interfere with the film.
Thus, in the known arrangement described above, the pressing means is spaced apart by a large distance from the processing head and the light-shielding member is positioned behind the pressing means. This arrangement poses a problem in that a large gap is formed between the pressing means and the light-shielding member when the electrophotographic film is pressed onto the processing head by the pressing means, with the result that the projecting light undesirably reach the frames other than the frame to be projected, thereby adversely affecting frames which carry latent images which have not been developed yet.